Carburetor



C. H. KIRBY Oct. 24, 1933.

CARBURETOR Filed Aug. 6, 1928 s Sheets-Sheet 1 CARBURETQR I I Filed -6. 1928 e Sheets-Sheet 2 Oct. 24, 1933.

GARBU 'ts-sneet 3 Filed Aug. 6, 8

c. H. KIRBY 1,931,613

Oct. 24, 1933.

CARBURETOR 6 Sheets-Sheet 4 I Fi led Aug. 6, 1928 x Oct. 24, 1933. KIRBY v 1,931,613

CARBURETOR Filed Aug. 6, 1928 6 Sheets-Sheet 6 gwuemtoe Patented Oct. 24. 1933 CARBURETOR Charles H. Kirby, Flint, Mich, assignor to Marvel Carbureter Company, Flint, Mich, a corporation of Illinois Application August 6, 1928. Serial No. 297,698

16 Claims.

This invention relates to improvements in carburetors and more particularly to carburetors of the type disclosed in my co-pending applications, Serial Numbers 297,695, and 297,696 both filed Aug. 6, 1928.

In the first one of said applications I have disclosed a carburetor including means for constantly feeding an auxiliary supply of fuel into the main mixture passageway posterior to the throttle valve, as long as the engine is running. In the carburetor there disclosed I have also shown a U tube combined with a reserve supply well, the U tube being adapted on acceleration to furnish an auxiliary amount of fuel to the main nozzle and the well coming into play after this for supplying additional fuel to the nozzle during acceleration.

In the second mentioned application I have disclosed additional means for supplying the nozzle during acceleration with an intermediate reserve supply of fuel during the hiatus between the supply by the U tube and the well.

In both of said applications the Venturi throat or tube of the carburetor is provided in its entrance lip with a port which communicates with the reserve supplies, whereby the reserve supplies are subjected to sub-atmospheric pressures depending on the position of the throttle, and in this way the auxiliary feed posterior to the throttle is automatically diminished as the feed from the main supply is increased and vice versa.

The present invention pertains to improvements in the carburetors disclosed in my above mentioned copending applications and is directed specifically to the means for furnishing the intermediate auxiliary supply during acceleration in the hiatus between the supply by the U tube and the well.

The primary object of the present invention is to provide a carburetor with a reserve supply means including a pump adapted on the operation of the throttle, to force a reserve supply into an auxiliary chamber, such chamber being drained by the main nozzle before the auxiliary well comes into play. 0 I

Another object of the invention is to furnish a carburetor including special means for supplying auxiliary amounts of fuel during acceleration, such means comprising among other things a throttle operated pump designed to force fuel into one of the auxiliary supply chambers when the throttle is moved to open position.

With the foregoing objects outlined, and with other objects in view which will appear as the description proceeds, my invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

Referring to the drawings,

Figure 1 is a vertical sectional view of an embodiment of the present invention incorporated in a carburetor designed more especially with a view of clearly disclosing the essential features of the improvement;

Figure 2 is a side elevation of the same, partly in vertical section;

Figure 3 is a vertical sectional view, partly in elevation, of a commercial embodiment of the invention, the section being taken on line 3-3 of Figure 4;

Figure 4 is a bottom plan view of the commercial embodiment of the invention;

Figure 5 is a vertical section taken on line 5-5 of Figure 4;

Figure 6 is a similar view taken on line 6-6 of Figure 4;

Figure '7 is a side elevation partly in section, the section being taken on line 7'7. of Figure 4; and

Figure 8 is a vertical sectional view on line 8-8 of Figure 4.

Figure 9 is a diagrammatic view of the device.

In the embodiment of my invention illustrated in Figures 1 and 2, 1 designates an ordinary float chamber to which the liquid fuel is fed through a pipe 2. The float 3 operates the valve 4 which controls the supply into the float chamher.

As in the inventions disclosed in my before mentioned copending applications, fuel in the present carburetor, whenever the engine is running, is constantly fed through a tube 5, orifice member 6 and passageways '7 and 8 to the main mixture passageway 9 of the carburetor and is discharged into the mixture passageway at the point 10 which is above or posterior to the pivotally mounted throttle valve 11. Located in the passageway 9 'is an ordinary Venturi tube or throat 12 having a port 13 arranged in its entrance lip. This port communicates by duct 14, chamber 15 and port 16 with an annular space 17 surrounding the tube 5, whereby there is a means of communication between the chamber '7 and the mixture passageway 9.

From this it may be seen that when the throttle valve is in closed position as shown in Figure 1, maximum suction will be exerted at the point 10 and minimum suction at the point 13, and consequently a maximum supply of auxiliary fuel will be constantly fed from the chamber 1 through 5, 6, 7 and 8 to the passageway 9 above the throttle. On the other hand, as the throttle valve is opened, the velocity of the air entering at 18 and passing through the Venturi tube will increase and consequently sub-atmospheric pressure will be exerted in 14, 15, 16, 17 and 7 whereby the feed of auxiliary fuel through 8 will be diminished. In other words, as the throttle valve opens, the auxiliary feed through 8 will be automatically diminished and when the throttle valve 'is moved toward closed position, the feed through 8 will be automatically increased.

The carburetor includes a U tube consisting of a horizontal passageway 19, a main fuel nozzle 20 and a reserve leg 21. Fuel is normally fed to the passageway 19 from a chamber 22 by way of an orifice member 23. Fuel fiows into the chamber 22 through a duct 24 which leads as shown in Figure 2 from a pump barrel 25. The pump barrel is supplied with fuel by a duct 26 which, as shown in Figure 1, communicates with an angular conduit 2'7 that leads from a small chamber 28. The fuel from the float chamber flows to 28 through an orifice member 29.

It will thus be seen that whenever the engine is running and suction is exerted on the fuel nozzle 20, fuel will flow through 29, 28, 27, 26, duct 30, port31, chamber 25, duct 24, chamber 22, and an orifice member 23 into the nozzle 20. Through the same means, when the engine is idle, fuel will flow to the passageway 19 which supplies the same to the reserve leg 21.

Assuming the supply by such means, and referring to Figure 1, it may be seen that if the engine is running and the throttle valve 11 is open, the fuel from the reserve leg 21 will be drawn through the passageway 19 into the nozzle 20 and this will serve to furnish a rich mixture when starting the engine or for accelerating purposes.

The well heretofore mentioned is shown at 32 in Figure 1 and it will be noted that it commucates with both the passageways 26. and 27 so that this well will fill when the engine is stopped and will empty on acceleration due to suction through 26 when the reserve leg 21 has been emptied. To insure the operation of the well subsequently to the emptying of the reserve leg 21, the well is closed at its upper end and provided with an orifice member 33. The opening in the orifice member communicates with the chamber 15 and the reserve leg 21 has its upper end open as shown at 34 and this open end communicates with the passageway 14. As the opening 34 is larger than the opening in 33, it will be appreciated that the suction through 13 will allow 21 to empty before 32.

Referring to Figure 2, it will be noted that a lever 35 is fast on the shaft 36 of the throttle valve and this lever is pivotally connected to a link 37 that joins the same to the stem 38 of the pump. This stem passes through a packing gland 39 and slides in a bearing or guideway 40 'in the top of the pump barrel. Arranged in the barrel and mounted on the stem is a piston 41 which is normally forced upwardly by a coiled spring 42 which bears at its lower end upon an orifice member 43, in which the orifice 31 is located.

The stem is reduced in size at its lower half as shown at 44, in order that it may pass freely through the orifice 31 without closing the latter at any time, and the portion 45 of the stem is reduced still more, whereby when the stem is depressed, the clearance between the wall of the. orifice 31 and the stem will be increased to allow an increased passage of fuel from 30 into 25.

A port 46 leads from the chamber 30 to an orifice member 47, shown in Figure 1, and when fuel is forced by the pump through 46 and 47, it will enter an auxiliary well 48 which communicates with the interior of the reserve leg 21 by :1 lower port 49 and. an upper port 50. The port 49 allows fuel from the well 48 to flow into the passageway 19 and the port 50 permits the subatmospheric pressure in 14 and the leg 21 to communicate at certain times with the well 48.

A ball valve 51 is arranged in the chamber 30 and is adapted to close the port 26 when the pump piston is depressed, and a ball valve 58 normally closes the orifice member 47 but is adapted to be unseated by fuel entering from 46 when the pump piston is depressed.

The reserve leg 21 is provided at its upper end with a ring 53 from which a pipe 54 is suspended into the leg 21 in spaced relation to the latter to provide an annular chamber or passageway 55. Owing to this construction, it will be appreciated that after fuel in the leg 21 has descended below the lower end of the tube 54, the sub-atmospheric pressure from 14 may be communicated by 55 and 50 to the chamber 48.

Referring now to the operation, as before stated, fuel will constantly fiow from 28 to 22 whenever the engine is running and the throttle valve 11 is open to any extent. If the parts are in the position shown in Figure 1, before the engine is started, the legs 20 and 21 of the U tube, as well 1110 as the passageway 19, will be filled with fuel due to gravity feed, but there will be no fuel in the chamber 48 above the lower end of the tube 54, because of the air trapped in this chamber. The well 32 will also be filled at this time and the pump barrel will be filled. If the engine is now started and the throttle valve is opened slightly, the air passing through the mixture tube 9 will draw fuel from the nozzle 20 and if the throttle valve is opened far enough, the nozzle will not alone be emptied but the suction will be felt in the reserve leg 21 and the fuel will also be drawn from this leg through the nozzle 20. Now if the throttle is opened far enough, the pump piston 41 will be depressed to an extent where the fuel in the upper portion of the pump barrel will be forced through 46 and 47 into the chamber 48, and as the pressure exerted by the pump will be super-atmospheric, the liquid will be rapidly transferred from the upper portion of the pump barrel to the chamber 48. When the fuel in the reserve leg 21 has flowed out through 19, if the suction through the nozzle 20 is continued, then the pumped fuel will flow from 48 through 49 to the main nozzle. After 48 has been emptied, if the suction in 20 is continued, the well 32 will also be emptied and after the fuel has been exhausted from these reserve supplies, the fuel will continue to feed from the" float chamber through 28, 27, 26, 30, 31, 25, 24, 22, 23, to the main nozzle 20.

It will be noted that the opening at 34 is larger than that at 50 and that the opening 50 is larger than that in the orifice member 33, and conse- 145 quently the suction exerted through 13 will modify the feed of the reserve supplies but will permit the same to be sequentially exhausted.

A pin 60 extends across the chamber 30 to limit the movement of the ball 51 in one direc- 150 tion and a similar pin 61 extends over the ball 52 to prevent the same from being misplaced.

In the commercial embodiment of the invention shown in Figures 3 to 8 inclusive, the parts are similar in structure and in function to analogous parts shown in Figures 1 and 12 but are differently arranged to facilitate manufacture and compactness, and to avoid repetition, I have added the letter a" to the numerals designating these corresponding parts in the commercial embodiment,

It will be apparent to those skilled in the art that various alterations may be made in the structures disclosed without departing from the spirit of the invention as expressed in the appended claims.

What I claim .is:

1. In a carburetor, a mixture passageway, a nozzle for feeding fuel to the passageway, a reserve fuel supply leg communicating with the nozzle means, an inner tube suspended in the reserve leg spaced from the latter and having its lower end terminating above the lower end of the reserve leg, an annular chamber surround ing the reserve leg, a port placing the upper portion of said chamber in communication with the space between the leg and the tube, a "pas sageway placing said space in communication with the mixture passageway of the carburetor, a port placing the interior of the reserve leg and the lower portion of the chamber in communication, and means for forcing fuel into said chamber.

2. In a carburetor, a mixture passageway, nozzle means for feeding fuel to the passageway, a reserve fuel supply leg communicating with the nozzle means, an inner tube suspended in the reserve leg spaced from the latter and having its lower end terminating above the lower end of the reserve leg, a chamber adjacent to the reserve leg, a port placing the upper portion of said chamber in communication with the space between the leg and the tube, a passageway placing said space in communication with the mixture passageway of the carburetor, a port placing the interior of the reserve leg and the lower portion of the chamber in communicatiom'and means for forcing fuel into said chamber, the last mentioned means including a pump.

3. In a carburetor, a mixture passageway, nozzle means for feeding fuel to the passageway, a reserve fuel supply leg communicating with the nozzle means, an inner tube suspended in the reserve leg spaced from the latter and having its lower end terminating above the lower end of the reserve leg, an annular chamber surrounding the reserve leg, a port placing the upper portion of said chamber in communication with the space between the leg and the tube, a passageway placing said space in communication with the mixture passageway of the carburetor, a port placing the interior of the reserve leg and the lower portion of the chamber in communication, and means for forcing fuel into said chamber, the last mentioned means including a pump actuated from the throttle valve of the carburetor.

4. In a carburetor having a constant level fuel reservoir, a carbureting passage provided with a throttle valve, a nozzle for constantly admitting fuel into said carbureting passage from said constant level reservoir below said throttle valve during the normal rurming of the engine, a plurality of auxiliary fuel reservoirs for successively supplying fuel to said nozzle, means including a pump for supplying fuel to said nozzle and one of said'reservoirs, when the engine is accelerated and means for regulating the supply of auxiliary fuel from said auxiliary reservoir to said nozzle by the velocity of air passing through said carbureting passage. 1

5. In a carburetor having a constant level reservoir, a carbureting passage provided with a throttle valve, a nozzle for constantly admitting fuel to said carbureting passage below said throttle valve from said constant level reservoir, a plurality of, au xiliary reservoirs for successively supplying fuel to said nozzle, means including a pump for supplying auxiliary fuel to said nozzle when the engine is accelerated and means for regulating the supply of auxiliary fuel to said nozzle from said auxiliary reservoirs by the velocity of air passing through said carbureting passage.

6. In a carburetor having a constant level reservoir, a carbureting passage provided with a throttle valve, a nozzle for admitting fuel to said carbureting. passage below said throttle valve from said constant level reservoir, a plurality of auxiliary fuel reservoirs for supplying fuel successively to said nozzle, a pump for supplying auxiliary fuel to said nozzle and one of said reservoirs and means for placing subatmospheric pressure on the fuel in the auxiliary reservoirs by the velocity of air passing through said carbureting passage.

7. In a carburetor having a constant level reservoir, a carbureting passage having a .throttle valve for regulating the flow of explosive mixture through said carbureting passage, a nozzle disposed in said carbureting passage for constantly feeding fuel into said passage from said constant level reservoir, a plurality of auxiliary reservoirs for feeding fuel successively to said nozzle, 2.

pump movable with the throttle for supplying an comprising a passageway entering said carbureting passage in the direction reverse to the direction of travel of the air therethrough for placing sub-atmospheric pressure on the fuel in the auxiliary reservoirs by the velocity of air passing through said carbureting passage.

8. In a carburetor having a constant level reservoir, a carbureting passage provided with a throttle valve, a nozzle in said carbureting passage for feeding fuel constantly'from said constant level reservoir, a plurality of auxiliary fuel supply means for feeding fuel successively to said nozzle, said auxiliary supply means including a force feed device acting in synchroniam with said throttle valve for forcing fuel to said nozzle and to one of said auxiliary reservoirs and means communicating with the carbureting passage for placing sub-atmospheric pressure on the fuel in said auxiliary reservoirs by the velocity of air passing through said carbureting passage.

9. In a carburetor having a constant level reservoir, a main fuel nozzle fed constantly from said constant level reservoir,a reserve leg in communication with said nozzle and said constant level reservoir, a force feed device cooperating with the reserve leg to feed an additional supply of fuel to said nozzle and means to modify the feed of fuel from said additional supply reservoir, a carbureting passage, a throttle valve for controlling the flow of explosive mixture through said passage, means for constantly feeding fuel in various amounts from the constant level reservoir to said carbureting passage and for introducing the same into the carbureting passage at a point posterior to the throttle valve, a nozzle disposed in said carbureting passage forming a main supply of fuel for said carbureting passage, fuel conducting means connecting the supply with said nozzle, a plurality of reservoir supply means including a pump cooperating with the throttle valve for increasing the supply of fuel to said nozzle and to one of said auxiliary supply means.

11. In a carburetor having a constant level reservoir, a carbureting passage having a throttle valve for controlling the passage of explosive mixture therethrough, a nozzle supplied constantly with fuel from said constant level reservoir, means controlled by the movement of the throttle for metering the supply of fuel to said nozzle from said constant level reservoir, a plurality of auxiliary reservoirs supplied with fuel from said constant level reservoir for successively supplying an auxiliary supply of fuel to said nozzle and means for controlling the supply of fuel from said auxiliary reservoir to said nozzle by the velocity of air passing through said carbureting passage.

12. In a carburetor having a constant level reservoir, a carbureting passage provided with a throttle valve for controlling the passage of explosive mixture therethrough, a 'nozzle for constantly delivering fuel to said carbureting passage from said constant level reservoir, a metering device for metering the fuel delivered from said constant level reservoir to said nozzle, a plurality of auxiliary reservoirs for successively feeding fuel to said nozzle and a pump controlling said metering means and operated by the throttle valve for forcing fuel to said nozzle as the throttle valve is moved into open position.

13. In a carburetor having a constant level reservoir, a carbureting passage having a throttle valve controlling the passage of explosive mixture therethrough, a nozzle for feeding fuel into said carbureting passage from said constant level reservoir, means controlled by the throttle valve for metering the supply of fuel to said nozzle, a plurality of auxiliary reservoirs supplied with fuel from said constant level reservoir for successively supplying fuel to said nozzle and means for modifying the feed of fuel from said plurality of auxiliary reservoirs by the velocity of air passing through said carbureting passage.

14. In a carburetor, a mixture passageway, a. nozzle for feeding fuel to said passageway, a reserve fuel supply leg communicating with said nozzle, a chamber communicating with said nozzle, said chamber having concentric vertically disposed tubes spaced apart disposed therein, the lower end of the inner tube terminating above the lower end of the outer tube, ports arranged in the upper and lower ends of the outer tube through which fuel and air are adapted to pass, a throttle valve for controlling the flow of explosive mixture through the passageway, a pump arranged to act in synchronism with the throttle for furnishing an auxiliary supply of fuel to said nozzle and means for placing sub-atmospheric pressure on said reserve fuel supply by the velocity of air passing through the mixture passageway.

15. In a carburetor having a constant level reservoir, a carbureting passage having a throttle valve for regulating the passage of explosive mixture therethrough, a nozzle extending to said carbureting passage for feeding fuel constantly from said constant level reservoir into said carbureting passage below said throttle valve, a passageway extending from said nozzle to said constant level reservoir for furnishing fuel to said nozzle during the normal running of the engine, a plurality of reservoirs supplied with fuel from said constant level reservoir, means for placing sub-atmospheric pressure on the fuel in the reservoirs by the velocity of air passing through said carbureting passage to modify the feed as the throttle valve is moved and a pump operated by the throttle valve for forcing fuel from said constant level reservoir to said nozzle and to one of said auxiliary reser- VOIIS.

16. In a carburetor having a constant level reservoir, a carbureting passage provided with a throttle valve, a nozzle for constantly feeding fuel from said constant level reservoir to said carbureting passage, a reserve fuel supply leg communicating with said nozzle, an auxiliary reservoir communicating with said nozzle including a vertically disposed tube provided with ports at its upper and lower ends through which fuel and air are adapted to pass, a pump arranged to act in synchronism with the throttle for furnishing an auxiliary supply of fuel to said nozzle and to said auxiliary reservoir and means for placing subatmospheric pressure onthe fuel in the auxiliary reservoir comprising a passageway extending therefrom and entering the carbureting passage in the direction reverse to the direction of travel of the air passing therethrough. 

